Research On Synchronous Control Decoupling Technology Of Two-Point Inertial Excitation Fatigue Test Of Wind Turbine Blade

Wind power blade full-size fatigue test is the most direct method for testing the life of the blade,at present,the domestic blade fatigue test mainly uses a single inertial excitation method,but there is a shortcoming of the low-driving force in the single inertial excitation,and the high test bending moment distribution accuracy is low.Although two-point inertial vibrations can improve these problems,in the vibration of the blade,there is a coupling effect between the two exciters and the blade,and the fatigue test is performed outdoors,which makes the difference between many external interference factors and electrical characteristics.This coupling effect becomes more complicated.This coupling effect becomes more complicated.Therefore,this article through in-depth study of the influence of the coupling effect on the vibration exciter during the blade vibration process,designs a synchronization control scheme and decoupling algorithm to achieve a good synchronization control of the two vibration exciters.First,by reasonable simplification of the blade vibration model,its moving differential equation is established,and the simulation model of two-point inertial excitation vibration system for wind power blades is established by the state equation of the asynchronous motor.By setting a certain simulation parameter,the effect of coupling effect on the phase of the two excitations in the vibration process is analyzed by setting a certain simulation parameter.The simulation results show that the phase difference and the speed of the two excitations in the ideal conditions are different from zero value,the blade amplitude is stable,and the vibration system reaches the resonance state.However,the field test in the uncontrolled state shows that due to the difference in the electrical characteristics of the drive and the electromagnetic interference of the test site,the coupling effect in the blade vibration system makes the two vibration exciters show a trend of gradual synchronization,but the speed difference and phase difference fluctuations are large,and the blade amplitude is difficult to stabilize.Secondly,in order to achieve precise decoupling of the vibration system,a synchronous control scheme and decoupling algorithm are designed respectively.Among them,the speed control adopts the asynchronous motor vector control scheme,so that the asynchronous motor has better speed regulation and anti-interference performance;The phase synchronization selects a virtual spindle synchronization control scheme based on fuzzy PID.By following the virtual reference signal and combining the advantages of the fuzzy PID algorithm,the robustness of the control system and the control accuracy are improved.The above-mentioned synchronization control scheme and decoupling algorithm are added to the vibration system simulation model,and the results show that the synchronization control scheme and decoupling algorithm have good effects in accelerating the synchronization speed and controlling the phase difference.The field test results under the synchronous control state are consistent with the simulation test results,verifying the effectiveness of the synchronous control scheme and decoupling algorithm,which can make the two vibration exciters and the blade enter a stable resonance state.Finally,summarizes the Lab VIEW-based fatigue test control system upper machine interface and the lower machine PLC program.The control system has good operational stability,and can realize real-time detection and recording of the speed difference,phase difference,blade amplitude and effective vibration times of the two vibration exciters.